Personally, I think it would result in Lucifer doing a little recruiting from the other side himself; especially among those Archangels with a thing for fairness.
After all, here are three demons that defied God's will, wreaked untold havoc, and were let back into heaven with little more than a slap on the wrist and significantly more authority than they had when they left.
Dominic, Marc, Gabriel, Lithroy and Blandine strike me as the set most at risk. I doubt Lucifer could get all of them, but one Fall and one self-exile would still serve to unsettle heaven and keep it from completely taking advantage of the situation.
I also have a few pet theories about what might go on inside hell proper. For example, I think
Irony would take over for Dark Humor without much fuss or bother. But on the whole I like Jason's ideas.